Shelf support



FIG. 1 is a perspective view of a shelf support;

FIG. 2 is another perspective view of the object seen in FIG. 1;

FIG. 3 is a front view of the object seen in FIG. 1;

FIG. 4 is a side view of the object seen in FIG. 1;

FIG. 5 is a top view of the object seen in FIG. 1; and,

FIG. 6 is a bottom view of the object seen in FIG. 1.

The broken lines depict environmental subject matter only and form no part of the claimed design. 

The ornamental design for a shelf support, as shown and described. 